This is how wireless network work

        WiFi Wireless networks work using radio waves instead of wires to transmit data between computers. That's the simple version. If you're curious to know what's going on in more detail, then it's all explained in this article.

I'm sure you know that computers transmit data digitally, using binary: ones and zeros. This is a way of communicating that translates very well to radio waves, since the computer can transmit ones and zeros as different kinds of beep. These beeps are so fast that they're outside a human's hearing range -- radio waves that you can't hear are, in fact, all around you all the time.

The way it works is a lot like Morse code. You probably already know that Morse code is a way of representing the alphabet so that it can be transmitted over radio using a dot (short beep) and a dash (long dash).More importantly for this example, though; it is a binary system, just like a computer's ones and zeros. You might think of wireless networking, then, as being like Morse code for computers. You plug a combined radio receiver and transmitter in, and the computer is able to send out its equivalent of dots and dashes (bits, in computer-speak) to get your data from one place to another.

You might wonder how the computer could possibly transmit enough bits to send and receive data at the speed it does. After all, there must be a limit on how much can be sent in a second before it just becomes useless nonsense, right? Well, yes, but the key to wireless networking is that it gets around this problem.

First of all, wireless transmissions are sent at very high frequencies, meaning that more data can be sent per second. Most wireless connections use a frequency of 2.4 gigahertz (2.4 billion cycles per second) -- a similar frequency to mobile phones and microwave ovens. As you might know, though, a frequency this high means that the wavelength must be very short, which is why wireless networking only works over a limited area.

In addition, wireless networks make use of a technique known as 'frequency hopping'. They use dozens of frequencies in the range they are given, and constantly switch between them. This makes wireless networks more immune to interference from other radio signals than they would be if they only transmitted on one frequency.

The final step is when it comes to all the computers on a network sharing Internet access. This is done using a special piece of wireless equipment called an access point. Access points are more expensive than wireless cards for one computer, as they contain radios that are capable of talking to around 100 computers at the same time, and sharing out access to the Internet between them. Dedicated access points are only really essential for larger networks, though -- if you only have a few computers, it is possible to use one of them as the access point, or you could just get a wireless router.

That's all well and good, then, but how does wireless equipment made by entirely different companies manage to work together when this is all so complicated? Well, the answer is that there are standards that all wireless devices follow. These standards are technically called the 802.11 standards, and are set by the IEEE (Institute of Electrical and Electronics Engineers). It is thanks to people sticking to their standards that wireless networking is so easy and cheap to use today.

Password Protect Compressed (zipped) Folders

How to Compress Folders and Files
To compress all files and sub-folders inside a folder, right click on the folder in Windows Explorer. To compress a file, right click on the file in Windows Explorer. After that, choose “Send To”. And when sub-menu comes out, click and select “Compressed (zipped) Folder”. Windows will now compress all the contents inside the folder or the file and create a compressed folder, more commonly known as zipped file. Rename the compressed folder to your desired name, and if you want, delete the original file or folder.
To compress multiple files and/or multiple folders, just launch the Windows Explorer, and select all the files and folders (sub-folders will be included automatically) by holding the Ctrl key while clicking. If you want to select files and folders that listed continuously, just holding the Shirt key, select the first item and the last item, and all items between them will be selected. Once selected, again, right click and click on “Send To”, and then “Compressed (zipped) Folder”. The name of the compressed folder will be based on the first file been compressed, so locate it and rename it to something meaningful. Delete the original files if you want.
How to Password Protect Compressed Folder
If you want to enhance the security and do not want others to view the contents of your compressed folder, you can assign password to the compressed folder or zip file. Locate your compressed folder or zip file in Windows Explorer or My Computer, then open the folder by double clicking on it. From the File menu, choose “Add a password…” (Encrypt in Windows Me), and key in your password twice then click on OK.

Note that all of the files in compressed folder are password-protected at the time of encryption or password adding. Any subsequent files will not be password-protected, to password protect subsequent files, the password needs to be removed and added again.
Note: Add a password to compressed folder (ZIP) is only available in Windows XP. Windows Vista and Windows 7 have removed such option, and user has to use third-party tool such as SecureZIP to password-protect compressed folders.
How to Remove and Disable Compressed Folder (zip file) Password
To remove the password of compressed folder or zipped file, just locate and open the compressed folder by double clicking it in Windows Explorer or My Computer, then from File menu, choose “Remove password” (“Decrypt” in Windows Me).
Tips and Tricks
1. Instead of compressing existing files or folders, it’s possible create an empty zipped and compressed folder to store future files in. Just go to the folder you want to store your compressed folder, click the “New” from File menu or from menu after right-clicking inside the folder. Then choose Compressed (zipped) Folder. Type in the name for the compressed folder.
2. To protect your sensitive files and folders on your PC from viewing by others, just send them to compressed folders and add a password to the compressed folder to keep it private.
3. You can drag and drop files or folders to a compressed folder. To do this, open the compressed folder first. Drag and drop does not move the files into the compressed folder, but copies them. If you want to move the files, hold down the Shift key when droping the files into the compressed folder. Alternatively, you can manually delete the existing files.
4. Same with drag and drop, Send To function does not move the files either. To move, delete the existing files manually.
5. File names in password-protected compressed folder are visible even though the files themselves are inaccessible without the password. To hide them, create another compressed folder (not necessary to be password-protected) inside the compressed folder which will be password protected. With this, those unauthorised users can view the contents of protected zip file, which is another zip file, but not the contents inside the secod zip file.

Restore Your System When You Can't Launch System Restore

System Restore automatically backs up the state of Windows and your installed programs (but not your data). When Windows misbehaves, System Restore allows you to return the operating system to a previous condition. So when System Restore misbehaves, you may be tempted to pick up your laptop and smash it into the wall.

That's not recommended.

Let's start with the basics: To launch System Restore in Windows 7 or Vista, click Start, type system restore, and press ENTER. In XP, select Start>All Programs>Accessories>System Tools>System Restore.

Now, onto Linda's problem:

Malware often blocks System Restore, so its failure to run could be a sign of infection. Before you do anything else, see Remove Hard-to-Kill Malware and follow the recommendations there.

If that doesn't solve the problem, try running System Restore in Safe Mode: Boot your PC and press F8 just before Windows starts loading. Getting the timing right can be tricky; you may need to press and release it over and over until you get the desired result.

That result is a simple, text-based menu. Use the keyboard arrow keys to select Safe Mode. Then launch System Restore as described above.

If that doesn't work, Windows 7 users have another option: the Windows 7 System Repair Disc.

To create it, in Windows 7, select Start, type system repair disc, press ENTER and follow the prompts. You'll need a blank CD-R and an optical drive that can burn one.

Once the disc is burned, leave it in the drive and reboot your PC. Keep an eye on the screen. When you're prompted to "Press any key;" do so.

Follow the prompts until you get to the "Choose a recovery tool" page. Then select System Restore.

Source: PCWORLD